1. Field of the Invention
The present invention relates to a door closer assembly and, more particularly, to a mounting for a door closer arm which permits the associated door both free-swing and regular-closer modes of operation.
2. Description of the Prior Art
In the prior art, there are disclosed a number of door closers of the electro-mechanical type wherein the closer, once the door is in open position, does not close the door until the activation or deactivation of an associated electric circuit. Such a circuit may be controlled manually, or automatically, as by a smoke detector.
Closers of this sort are well disclosed in prior patents such as U.S. Pat. No. 4.050,114, issued Sept. 27, 1977 to Richard L. Zunkel and U.S. Pat. No. 3,852,846, issued Dec. 10, 1974 to Loren E. Slaybaugh. Such closers generally comprise a cylinder containing a piston connected to the door by an operating arm. The piston in such a unit is spring-biased for movement in a direction which tends to close the door and such movement is opposed by an oil system which is relaxed only upon the opening of a solenoid valve.
More specifically, the door is opened manually thereby "cocking" the closer by winding back the door operator arm and moving the piston to compress the spring. The operator arm remains in the cocked position until the solenoid valve is opened as by an interruption in its electric supply. The opening of the solonoid valve, of course, permits the oil to flow in the closer and allows the spring bias to move the piston in the door-closing direction to close the door.
The closers disclosed in the above-mentioned patents are especially well adapted for use in nursing homes and hospitals to control metal doors of considerable weight and ruggedness.
In the past, because it is sometime desirable to close the door at will, provision has been made for overcoming or rendering ineffective the solenoid valve to permit the door closer to close the door. In the Zunkel and Slaybaugh closers, the provision has involved "momentary release pressure" usually ascomplished by the patient or nurse in pulling or pushing the door forcibly toward a closed direction. Once the initial closing force is used, the remainder of the closing is accomplished under minimum pressure. In re-opening the door, however, it is once again necessary to "re-cock" the door closer. The exertion required by the "momentary release pressure" and re-cocking of the closer has been a considerable obstacle especially for a debilitated patient. There has thus been a desire to keep the door closer in its cocked condition but to simply disengage or nullify the closer to permit the "free wheeling" or unimpeded swinging of the door.
One attempt to satisfy this desire is disclosed in the U.S. Pat. No. 4,034,437 to Lyman H. Robertson et al, issued July 12, 1977. In this arrangement, the arm is not attached to the door and remains in the cocked position out from the wall. When activated, the arm, which has a downward finger, swings encountering the door and eventually bringing it closed. Such prior arrangements, however, have been aesthetically repelling and objectionable in that they cause the door to "bounce" ahead of the arm when the arm is actuated.